Broken hack saw blade holder



Nov. 30, 1954 L. J. BEHR BROKEN HACK SAW BLADE HOLDER Filed Sept. 28. 1949 United States Patent Oiice 2,695,641 Patented Nov. 30, 1954 BROKEN HACK SAW BLADE HOLDER Leo J. Behr, Bridgeport, Conn.

Application September 28, 1949, Serial No. 118,360 2 Claims. (Cl. 1454-35) This invention relates to hack saw blades, and has for an object to provide an improved means for mounting a broken hack saw blade in the saw frame, so that when the blade is broken it is not necessary to `throw it away as is now common practice, but it is possible to continue using the blade.

Another object is to provide a device of `this character in which the piece of broken blade may be used as a se curing means for fastening the remainder of the blade at one end to the frame.

Another object is to provide a construction in which the broken end of the blade may be automatically secured to the frame by the act of tightening up the blade in the frame.

A further object is to provide a blade with improved strengthening means which will decrease the liability of the blades breaking in use, and further will provide a guide means for the blade in the cut or kerf in the work as the blade is used, which will hold the blade straight during the cutting operation and prevent its inclining to one side, and thus will make a straighter cut and greatly reduce the liability of the cut being inclined or directed to one side. l

With the foregoing and other objects in view, I have devised the construction illustrated in the accompanying drawing forming a part of this specification. It is, however to be understood the invention is not limited to the speciic details of construction and arrangement shown, but may embody various changes and modications within the scope of the invention.

In this drawing:

Fig. 1 is a partial side elevation and partial section of a broken standard hacksaw blade showing a portion of the frame and the connecting device;

Fig. 2 is a side view of a standard hacksaw blade;

Fig. 3 is a detail section substantially on line 3-3 of Fi 1;

ig. 4 is a partial side elevation and partial section showing a modified construction of the securing means for the broken blade;

Fig. 5 is a side view of the securing means showing the locking wedge in released position;

Fig. 6 is a longitudinal section of the blade and securing means of Figs. 4 and 5 and also showing a portion of the frame in section;

Fig. 7 is a side view of the wedge used in the form of the device shown in Figs. 4 and 5; i

` Fig. 8 is a View similar to Fig. 4 showing another modification;

Fig. 9 is a side view of a still further modication;

Fig. l is a transverse section substantially on the line 14)-10 of Fig. 9;

` Fig. 1l is a longitudinal section of the device of Fig. 9, and

Fig. 12 is an enlarged section of a portion of a piece of work and my improved blade in the cut illustrating the improved operation of this blade.

It is well known that hacksaw blades aremade very hard and this hardness makes them very brittle, causing extensive breakage of these blades in use, and they are generally thrown away as when broken there is no way of securing them in the frame. It is therefore an object of this invention to provide means whereby the broken `blade may be mounted in the frame and used until it is worn to the point Where it is no longer usable, thus permitting use of the blade even though broken for the normal life of the blade if it had not broken, and therefore greatly reducing wastage in use of the blades and of course reducing costs.

In the form of Figs. l, 2 and 3 a standard hacksaw blade is shown at 1 provided with the usual openings 2 at its opposite ends for mounting it in the frame in which the blade is used, two spaced arms of which frame are shown at 3 and 4. However, the connecting bar is omitted. In one arm is the supporting element carrying the inclined` pin 6 for insertion in the opening 2 at one end of the blade, and in the other arm 4 is the slidable support or bolt 7 carrying a similar inclined pin 8 for insertion in the opening 2 in the other end of the blade, this support or bolt 7 being threaded at its outer end 9 for an adjusting wing nut by which the proper tension may be placed on the blade and support it in the frame. It will be assumed now that the blade 1 has been broken at a short distance from one end, as indicated at the point 11, thus producing a short end piece 12. The end portion with the opening 2 may be broken off at about the location of the dotted line 13, leaving a short length of blade 14 having the teeth 15 along one edge. A holder or connector 16 is provided which has a at end portion 17 provided with an opening for the mounting pin 8 and at the opposite end includes a hollow at housing, or boxlike portion or head 18 in which the chamber on the inside is slightly wider than the thickness of the blade 1 and is open at the right hand half of the end 19 opposite and in alignment with the portion 17 to receive the broken end 2t) of the longer part of the blade 1, as shown in Fig. l. The other or upright portion of the other end of this boxlike construction 18 is closed as indicated at 21, but is open at its lower or opposite end 22 so that the short broken piece 14 may be inserted in this boxlike structure through this lower open end to one side of the inserted end portion 20, as shown in this View, and with its teeth opposed to the teeth 23 of the end 20, but, however, reversed with relation to these teeth as indicated. On the opposite side of the structure 18 is a screw 24 threaded in the edge of the structure and pressing at its inner end against the edge of the inserted end opposite the teeth 23. To secure greater lengthof thread for this screw an insert 25 may be provided on the inner side of the side wall and secured by welding or other suitable means. `Now with the parts in the position shown in Fig, l, if the screw 24 is screwed inwardly it will force the inserted end 20 of the blade to the left and lock its teeth 23 with the teeth 15 of the broken insert 14. Then by tightening up on the wing nut 10 the belt 7 may be drawn tightly in the frame in the usual manner, this bolt being secured to the blade 1 through the interlocking of teeth 15 and 23 of the two portions of 1 blade, the insert 14 being held in the structure 18 by the end wall 2l. Thus the broken blade can now be used the same as a whole blade.

i In the form of thedevice shown in Figs. 4 to 7, the splicing or means for attaching the broken end of the blade 1a to the leg 4 of the frame comprises a device 26 is wider than the blade so that its edge 31 is spaced away from the edge of the inserted blade. This edge is also inclined, as shown, so as to provide between this edge wall and the blade a tapered space 32. In this space is inserted a tapered or wedge-shaped locking element 33 which is made substantially the thickness of the blade and iii) has along one edge a series of teeth 34 corresponding to the spacing of the teeth 35 of the blade, while its opposite edge 36 is inclined to correspond with the edge wall 31. The space 32 is open at its lower or larger end 37 for insertion of this wedge-shaped locking element 33, as indicated in Figs. 4 and 5. In use, the element 33 and the broken end of the blade are inserted in the structure as indicated in Fig. 5, the element 33 being inserted as far as it will go, with the teeth 34 passing over the teeth 35. Then by tightening up on the bolt 7 the connector 26 is drawn downwardly, causing the inner surface of the inclined edge wall 31 to have a camming action on the corresponding inclined outer edge 36 of the element 33, and will force it to the right or inwardly tothe position of1 Fig. 4; with its teeth 3'4`interlocked with the teeth on the' inserted end portion" 30 o'f the" blade" 121'." or tension on the element 27 maintains this member 33 interlocked with the blade a'id will therefore prevent the bladeffr'onr b'eihg1ptil1ed2 ont 'of' tile-connector 26; antrjt will be rigidly attached to the frame, permittingfillrther useA of the'brbkenY-blade; A'-series-of`m'er`ribers' 331n`ay, be prov-ide I lngldifer'ent numbers`and"spacingiofthese te'e'tll' lrsp'oll't'ilg tfl'i blades With Vlr'lieh"they4 are to b'eSedl- Irlthe-forniV ofi Fig-8` lie'cennector 38is o f slightlyV differ t construction ine dingtle extension 39iprovided` With-f t-he-'opening '403 for insert-ion o'fl the frame pin" S and '1" o'theneridwith the' box or housingmstrucopen' at the topf to' receivethe broken' en d -1-"-` Th'estructhre'l" isf*somewhaty Wider than't 'ad forming a' space at `the left'ha'ndfside ofthe lade ln-1 which is'- mounted` a locking insert 421 This' may"- be permanently mounted in the structure 4l by'anysuitable meansQ-sueh; for example, as Welding, as shown? ttt-43, and the inner-l e'dge-of'this lockingV member is pro idedfwith a'- seiiesfo'fA teeth 44 corresponding to the spacing' of-[the teeth' 3"5`^ inithe blade but drectedin the opposite directionsb4 as t'o be opposed to them. The spacing infth'e'head'struc'ture 4T between-the free edges o'f` the# teeth 44" andthe oppositel edge 45 of the space within this head-ie somewhat' wider than thewidth of" the bladeltzyso'- that the end of thre'bladem'ay be insertedin the head@ 41".- I'n the ed'ge' 46"opposite"tojthe locking member 42-4 is mountedL a screw `47v with its inner end arranged' tb'- engage the edge'of` the blade lj'aj. With this' scr'evv'f" retracted the broken ed'geA of the blade may be inserted in the hollow head 41", and thenthe screw may be threaded-in to: force theblad to thev left and bring its teethlSSi-intoi-lo'ckingengagementvvith the teeth 44 ofthe insert 42';` asshownjin= Figi 8l This-securely locks the broken end of the'blade 1-'ato'the'c'onnector` element` 38L which' wi1l= now' be lised'toconnectV this end of the blade" tothe-tightening element 7 of the saw frame and"`per`rnitl further' use of the broken blade. More' threads may be' secured for' thescrew 47 either by thickening the side' wall 46 or by welding a" separate insert element 48011 the' inner side thereof.

Ih thearrailgement of Figs; 9g-l0 and 1`l the connector element 4'9-is'ajhol1o'w box-like housing structure openJ at' itsfup'per end 50;'forins'ert'ion of the blade 1b. This str-uc'ltre is also wider than the blade and open; at' its left hand sideat its lower end 51 for insertion'of' a Wedgeshape'dlockin'g element 52 corresponding t`o `the locking.' elemen't'of.' the form of Figs'. 4 and-5. Thistaperedor Wedgeshapedelem'e'nt has" a series of teeth 53' onitsi straight inner edge'lcorre'sponding to the spacing-of the teeth 54 ofthe blade andl facing inthev opposite directions'o` as to` beopposeditothelteeth 54. At its lefthand edgeth'is structure' 49'is inclined; as shown at 55; and the corresponding'edgeS of the'insert or wedge 52is` similarly tapered. This device is used the same as the form of Figs: 4 and 5. Th'atis", th'ejbroken'end of the blade 1b is inserted' in thelopeftix' endet) o' the connector 49an'd the locking member` 52 is inserted: fromrthe lower end to bring' its teeth 53 oppositeI theteeth 54l of the blade. Theil'- by'tghtening' up on the holding Velen'lent` or bolt 'Z the connector 4'9I sdrawn downwardly somewhat with relation-tothe blade" causingits-inclinedwall t'o'havel` a' cam'lliih'gy action on" the'- ed'ge- 56I ofy the insert 52" and therefore force? it tothe right-- tbcauseits teeth- 53:'y to interlock with the" teeth 54 of-- th'e inserted end porion ofhe blade. This effectively' loc'ks-the-connecto'rl 49to they broken endlofi tlief blade', and a'sthelcohnee-tor is secured-ltb the"I adjusting bolt 7 the'v blade may b`ef tightened as" previously-'described andmay' be' used thes'arilel as an'f unbroken blade;

The-blades 1aand' libv are provided with a series of longitudinally extending ribs o'r cormlgations 57 running' substantially the full? leng'thof the' blade,.thus forming.V longitudinal ribs and grooves 57 and 58 on oppositesidesr ofthe blade; This greatly strengthensfthe'blade, mate'- rially reducing'the-liability of breakage and these corrug-ations` or ribs also-provide-guiding means-for? the blade inthe cut as it'-l is formed.' in the" vvork-r to thus hold the bladey straight in" the cut;I preventing' it from inclining laterally. Thus' the blade will pass straight throughY the w'rkwith: a straight cut' insteadofa laterally inclined; er1-tf1 as@` is apt to'-. be formed unlessj the" operator is very 42 skilled and great care is taken to maintain the blade straiglt As is well known, the teeth of the blade are glven a set, that is, alternate teeth are bent laterally in opposite directions, as shown in Fig. l2, so as to make the width of the cut 59 in the work 60 slightly wider than the body of the blade to provide clearance and prevent binding of the blade as it passes through-the cut. To maintain this clearancei--the-Width-of the blade-betWeen-the high edges of the rib's"57` isrradeY slightly less than the distance between the onter edges:61= ofthe-teeth? providing a clearance space 62, which of course is greatly exaggerated in Fig. 12.- Tlef bladei\1b,--However';. isi provitledtwith teeth on both edges, the -edge oppositev teeth 44 being provided with teethef:v These tee "may be of the same size and number as the teeth 54, but it is preferred to provide a diierent number of teeth on the opposite edges so that the same blade maybe used for different types of' workl The ct made" byl the" teeth 63j howev somewhat* lessthan that orthe teeth- 5'4,' so@ that tft tance lbetween their'oppo'site'outeredges 64' is 'somewhat less than the'distance hetweenthe outer ed'ge's`61j offtheti teeth $4-,`y so-thata'stheblde follows-intotlretcutzsanratle bythe teeth 54 there will be clearancetbetweerttlieqtltel' edgesof these tee-tti p63? andA the; sides' of' the chti However; the setting-ortlteseteotlreatis sucll that'the ydistanceY between their-outer` edges 64 is-somewllat greaterj'than the thickness between the high points'of theoppositetibs' 57' so" that there clearance betweenjtheA sides of 'thegcnt and these rib'sr when eitheriside of the blade" isu'se'dlfr a saw'f-cut; For' example; tlte'widthbetween tltc'f-cdge's' may be and that ,between the edgesI 64 ol?` theteetlr" 63:' .085, ancl"' the [width betweenv the A high" pirrtsf57" on opposite sides""ofthebladeabout .0752 or evenasgreat as .080,y butthelesserthicknessisS-preferred`to"a ,fr' Wear of the outer' edges of the.' teeth"and"thi1s"niair`iti`rt the' clearance between" th'e: sides `of thecut and" the high surfaces ofthecofrr'iigations to'preverit"bin'ding,` y y In' the 'fbrn'riof the "device of Figs-1 4', 5`4 andgj .theblade has onlylongitdinal e1trovente-nt"in the connectotszc and 49. It is preferredwtoA shape these connetorstb" c'r-'re spond withF the blade; by corrugating'its Iside" wllszcorresp'o'lditig t0 the" blade Colfl'lltgtioriS',` 'slfdieatedf ats 6s "iff Fig; l0. However;` this-is notneeess'ary a thesde'walls' ofthe connectors could be straight otr and' spaced slightly greater'thanthedistance between th'euoter'edg'esf- 6Io`f the`ctt'ertee'th`. I I 1 In the form of Fig. 8, as theinserted`end"ofi-thez "'a'd`e` is shifted laterally in the connector 38,-,the side wllsf-of thisv` connecter' aire" not crrngter-lil blfitfare left ilati'and. spaced slightlyy greater than-' thewidth between theouterl' edges-of the teeth- 35; ,so`tha`t'th`e space-is' wide enough' for insertion '-o'f thebla'de y,

It" will beunder'stoodfrom the' above" that' tlis'1 dviocomprises a very simple and effective means for secr'ing" the' broltcn'endioff altacltsw' bladin' the Hacke-aw frame., permittingfur'ther use`o'f`the' blade after it sbrokenfan'd? thus permitting full use of the-blade until itt is worn" out," and removing' theheeessity of v'throwingthe broken '.blades: away until they are-so wor-fi; The connectorsv arema-d of th'e proper sfizefor'` the blades-'used aridmay. be'used with the smaller orhand saws", or'larger sizesl may bemade for usewith the larger or machine' operated-blades It will` beevident'thatl the connection of the broken'tend of the blade tof the conect'o'r may" be made easily andt quickly; and that by the use" of intc'rlockingtectlr the.4 broken end-of the blade-lis so-locked inthe connector that' there" is'no' danger' of its being. p'ulld from( it either in tightening the blade" in the" trarne' or in-the use of theblade.- The corrugations in the blade arefamaterialiimprovement'in nto'nlys'trengthening the blade to reduce breakage but also in guiding the blade in thecut-eso as-to keep `it"strjghtadmakeit' milch easier to make a straight cut; and" this' guiding" actionis`-secured' even. ina-shallow cut by `therst or second ribs'or corrugations immediatelyback of th'e cutter't'eeth. Any desired. number' offl thesev corruga'tion'sf maybe' ,used as -foti'nddesirableA orexpedient.Vy

1I -Iavin'g thus4 set forth the nature of my inventiomll c alm:

1. In a-l'i'a'ck' sa`vv-,'l ar blade comprisingay strip offmetall providelll withA longtdnal co'rruga'tions and; with an'. opening in one` e'nd for securing`v it to one arnti--of-aha'ele` saw frame, a' eoiiecto'rl'including': al housing;- stiguc-turepro-- vided with: arl" elongated opening for insertion irrt@ th@y hsingoabik'e endof'saidblade opposite said secur ing opening, holding means in the housing at one side thereof including a wedge-shaped member provided on one edge with a series of teeth facing in the opposite direction from the teeth on one edge of the inserted blade end and adjacent thereto, one side of the housing engaging the other edge of the wedge to shift it toward said blade to interlock its teeth therewith and hold it in this position to connect the broken end of the saw blade to said connector, at least one side wall of the connector being longitudinally corrugated to correspond with the blade, and said connector being provided with means for securing it to the other arm of said frame.

2. In a hack saw, a blade comprising a strip of metal provided with longitudinal corrugations and with an opening in one end for securing it to one arm of a hack saw frame, a connector including a housing structure provided with an elongated opening for insertion of a broken end of said blade opposite said securing opening into the housing and at least one side wall provided with corrugations corresponding with those of the blade, holding means comprising an insert in the housing provided with a series of teeth facing in the opposite direction from the teeth on said inserted portion of the blade and adjacent thereto, said insert being tapered with an inclined edge on the opposite side thereof from the teeth, the housing having a similarly inclined edge wall to engage said inclined edge of the insert and cooperate therewith to shift the insert toward the blade to engage its teeth with teeth on the inserted end of the blade by movement of the housing in a direction to withdraw it from the blade, and said connector being provided with means for connecting it to the other arm of the frame.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 877,146 Ward Jan. 21, 1908 1,043,405 Dogenais Nov. 5, 1912 1,173,164 Berkman Feb. 29, 1916 1,175,582 Bangent Mar. 14, 1916 1,369,178 Lawrence Feb. 22, 1921 1,410,310 Howard Mar. 21, 1922 1,512,904 Brennan Oct. 28, 1924 1,752,586 Bolinder Apr. 1, 1930 1,882,328 Kinkel Oct. 11, 1932 2,365,301 Shortell Dec. 19, 1944 FOREIGN PATENTS Number Country Date 36,392 Sweden Mar. 18, 1914 390,871 Germany Feb. 25, 1924 

